Pneumatic propulsion transportation system



March 29, 1966 E. BERGGREN NEUMATIC PROPULSION TRANSPORATION SYSTEM 9Sheets-Sheet 1 Filed Jan. 2, 1964 UQ cannon o ca na a na-naman ann-nunonN hm.

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INVENTOR. LLoBYYD E. .BERGGREN W VVUUUUU au A7' TORNEYS March 29, 1966L., E. BERGGREN PNEUMATIC PROPULSION TRANSPORATION SYSTEM 9 Sheets-Sheet2 Filed Jan. 2, 1964 m, .PE

March 29, 1966 L. E. BERGGREN 3,242,876

PNEUMATIC PROPULSION TRANSPORATION SYSTEM INVENTOR. LLOYD E'. BERGGREN4.32, AT TORNEYS PNEUMATIC PROPULSION TRANSPORATION SYSTEM 9Sheets-Sheet 4 Filed Jan. 2, 1964 VS N R E M m JE n QNRV v W G m l f N RQl 1 E o S m l MS E my 0B L L March 29, 1966 E. BERGGREN 3,242,876

PNEUMATIC PRoPULsIoN TRANSPORATION SYSTEM Filed Jan. 2, 1964 9Sheets-Sheet 5 mw "Wh, 'fn". muuu im H4 FIG. J6

INVENTOR. LLOYD EBsnccnE/v AT ToR/vEw/ s March 29, 1966 L. E. BERGGRENPNEUMATIC PROPULSION TRANSPORATION SYSTEM N s u l m j, e l G p/ N h N c5. w R mi .v mm 3 m s T 9 m E A D S .GN m/N. .GNR L B MN ohm. www w Mm Lwml u w 2, n. n w

March 29, 1966 L E. BERGGREN PNEUMATICI PROPULSION TRANSPORATION SYSTEM9 Sheets-Sheet 7 Filed Jan. 2,v 1964 INVENTOR LLOYD E BERGGREN ATTORNEYS March 29, 1966 1 E. BERGGREN 3,242,876

PNEUMATIC PROPULSION TRANSPORATION SYSTEM Filed Jan. 2 1964 9Sheets-Sheet 8 LLOYD E BEHGGREN A 7` TORMES/S March 29, 1966 l.. E.BERGGREN PNEUMATIC PROPULSION TRANSPORATION SYSTEM 9 Sheets-Sheet 9Filed Jan. 2, 1964 INVENTOR. .L/.oYo E BERGGREN BY y l WMM A7' TOR/VE YSUnited States Patent O 3,242,876 PNEUMATIC PROPULSION TRANSPORTATIONSYSTEM Lloyd E. Berggren, 4924 1st Ave. S., Minneapolis, Minn. FiledJan. 2, 1964, Ser. No. 335,157 23 Claims. (Cl. 1041-134) in transportingloads or passengers to given destinations in a minimum of time and witha maximum of safety.

Another important object of my invention is the provision of novel meansfor levitating and propelling a transport vehicle.

Still another object of my invention is the provision of atransportation system in which a vehicle is disposed in a guideway, andof novel guideway construction which incorporates an air duct extendinglongitudinally of the guideway for passage of air utilized in levitatingand propelling the vehicle. v

Another object of my invention is the provision of a transportationsystem as set forth, in which air under pressure to levitate and propelthe vehicle is supplied from stationary sources spaced from theguideway.

Another object of my invention is the provision of a transportationsystem which is adapted for use either on the ground surface, elevatedabove the ground, or disposed below ground level, as a subway, withequal facility.

Another object of my invention is the provision of a vehicle whichrequires no propulsion mechanism, fuel, or controls therein foreffecting movement thereof.

Another object of my invention is the provision of means for supplyingventilation to said vehicle during movement thereof. J

Another object of my invention is the provision of novel means forautomatically controlling a supply of air under pressure to levitate andpropel vehicles on the guideway, whereby to compensate for loadvariations in said vehicles.

Yet another object of my invention is the provision of means forautomatically maintaining a predetermined spaced relationship between aplurality of independent vehicles longitudinally of the guideway.

Another object of my invention is the provision of a system having aloading and unloading station area laterally displaced from the mainline of travel, and of novel means for moving a vehicle into saidstation area from said main line of travel and from the station area tosaid main line.

Another object of my invention is the provision of a pneumaticpropulsion mass transportation system which can be built, operated andmaintained at relatively low cost, and which is highly eicient inoperation, rugged in construction and durable in use.

To the above ends, I provide a Wall structure delining an elongatedcross sectionally generally U-shaped guideway having opposed side wallsand a bottom wall and a longitudinally extending air duct underlyingsaid guideway, and one or more transport vehicles having bottom portionsdisposed in the guideway for movement of the vehicles longitudinally ofthe guideway. The bottom portion of each vehicle cooperates with theguideway bottom wall to define a plenum, the guideway bottom wall havinglongitudinally spaced conduit portions in the nature of jet openingstherethrough for 3,242,876 Patented Mar. 29, 1966 Mice movement of airunder pressure from the duct to the guideway. Air under pressure issupplied to the duct from a suitable source, such as one or moreblowers, and the jet openings are disposed to direct air from said ductin directions to levitate the vehicle or vehicles and propel the same ina given direction longitudinally of the guideway, the vehicle beingdevoid of individual propulsion motors and related mechanism. Means inthe nature of valves are further provided for controlling movement ofair through said openings, whereby to limit passage of air from the ductto the guideway to control speed of the vehicles and the minimum spacingbetween adjacent ones of said vehicles longitudinally of the guideway.

The above, and still further highly important objects and advantages ofmy invention will become apparent from the following detailedspecification, appended claims and attached drawings.

Referring to the drawings, which illustrate the invention, and in whichlike reference characters indicate like parts throughout the severalviews;

FIG. l is a view in plan, partly diagrammatic, of atransportation systemproduced in accordance with my invention, some parts being broken away;

FIG.` 2 is an enlarged fragmentary View in perspective of a transportvehicle disposed in a portion of the guide# way of FIG. l, some partsbeing broken away and some parts being shown in section; f

FIG. 3 isan enlarged view corresponding to a portion of FIG. 1 showing avehicle extraction or deceleration area of the guideway of my inventionadjacent a station area thereof;

FIG. 4 is an enlarged view corresponding to a portion of FIG. 1 andshowing a vehicle insertion or acceleration area adjacent the stationarea;

FIG. 5 is an enlarged fragmentary section taken substantially on theline 5-5 of FIG. 3;

FIG. 6 is an enlarged transverse section taken on the line 6-6 of FIG.3, with some parts added and some parts being broken away;

FIG. 7 is an enlarged transverse section taken substantially on the line7-7 of FIG. 4, with some parts added and some parts being broken away;

FIG. 8 is an enlarged transverse section taken substantially on the line8-8 -of FIG. 1;

FIG. 9 is a fragmentary longitudinal section taken on the line 9-9 ofFIG. 8;

FIG. 10 is an enlarged fragmentary vertical section taken substantiallyon the line 10-10 of FIG. 3;

FIG. 11 is a view partly in horizontal section and partly in bottomplan, taken on the line 11-11 of FIG. 10;

FIG. 12 is an enlarged fragmentary vertical section taken on the line12-12 of FIG. 2;

FIG. 13 is a view in bottom plan of the vehicle of FIGS. 2 and 12;

FIG. 14 is a view corresponding to FIG. 13, but showing a modified formof plenum defining wall portion of the vehicle;

FIG. 15 is a fragmentary view in side elevation of the bottom portion ofa vehicle incorporating the structure of FIG. 14;

FIG. 16 is a view in side elevation of a further moditied form ofvehicle;

FIG. 17 is a view in bottom plan of the vehicle of FIG. 17;

FIG. 18 is a view corresponding generally to FIG. 5 but showing afurther modified form of vehicle, on a reduced scale;

FIG. 19 is an enlarged fragmentary view, partly in plan and partly inhorizontal section, taken substantially on the line 19-19 of FIG. 2,some parts being broken away and some parts removed;

FIG. 20 is a fragmentary view, partly in elevation and partly insection, taken substantially on the line 20-20 of FIG. 19;

FIG. 21 is a vertical section taken substantially on the line 2121 ofFIG. 19, on an enlarged scale;

FIG. 22 is an enlarged fragmentary view partly in elevation and partlyin vertical section, taken substantially on the line 22-22 of FIG. 19;

FIG. 23 is an enlarged fragmentary vertical section taken on the line23-23 of FIG. 19;

FIG. 24 is an enlarged fragmentary horizontal section taken on the line24-24 of FIG. 21;

FIG. 25 is an enlarged fragmentary view, partly in plan and partly inhorizontal section, taken on the line 25-25 0f FIG. 2l;

FIG. 26 is an enlarged fragmentary longitudinal section taken on theline 26-726 of FIG. 3 with portions of a pair of spaced vehicles added,and showing valve equipped air openings for levitating and propellingthe vehicles;

FIG. 27, sheet 4, is anenlarged fragmentary view in top plan, as seenfrom the line 27-27 of FIG. 26;

FIG. 28 is an enlarged fragmentary view in bottom plan, as seen from theline 28H28 of FIG. 26;

FIG. 29, sheet 3, is an enlarged fragmentary section taken on the line29-29 of FIG. 27;

FIG. 30, sheet 3, is a view partly in elevation and partly in transversesection, taken on the line 30-30 of FIG. 29;

FIG. 31 sheet 3, is an enlarged transverse section taken on the line3131 of FIG. 29;

FIG. 32, sheet 7, is, an enlarged fragmentary section taken on the line3232 of FIG. 30;

` FIG. 33, sheet 7, is a view corresponding to FIG. 32 but showing adifferent position of some of the parts;

FIG. 34, sheet 7, is a view corresponding to FIG. 29, but showing amodified arrangement;

FIG, 35 is a fragmentary view in perspective of a portien of thetransportation system of my invention, including an enclosure throughwhich the vehiclesl of my invention travel;

FIG. 36 is an enlarged fragmentary transverse section takensubstantially on the line 36-36 of FIG. 35;

FIG. 37 is a diagrammatic view of aguideway showing an interlockarrangement for the valves of FIGS. 27-32;

FIG. 38 is a fragmentary transverse `section of the guideway, taken onthe linel 38e-3S, ofFIG. 37; and

FIGS. 39, 40, and 41 are views corresponding. generally to FIG. 5, butshowing modified forms of. vehicle and guideway structure.

Referring with greater detail to the drawings, and with specialreference to FIGS. 1-13, thereof, a right-of-way 1 is shown ascomprising a pair of elongated guideways 2 and 3 disposed inside-by-side relationship as shown in FIG, 1, a portion of each guideway2 and 3 being laterally extended to provide a station area 4 andacceleration and deceleration areas 5-and 6 respectively, at oppositeends of their respective station areas 4, said` station areas 4including loading platforms 7, shown diagrammatically in FIG. l. It willbe appreciated that, while FIG. 1 shows a right-of-way in the form of asingle doubletracked loop having a single station 4, it is `intendedthat the system will involve as many guideways 2 and 3 as well asstation areas 4 as required in a given transportation complex or system.

The guideways 3 and 4 are defined by wall structure which cooperates todefine conduit means including a duct 8 underlying the guideways 3 and 4and extending longitudinally substantially the entire length of theright-ofway 1. the wall structure includes a pair of opposed sidemembers 9 and 1th, preferably in the form ofl structural steel channels,a central support membery 11 extending longi- In the embodiment of theinvention illustrated,`

tudinally of the guideways 2 and 3, and upper and lower walls 12 and 13.The central support member 11 is preferably in the nature of structureI-beams having longitudinally spaced openings 14 for free passage of airtherethrough. The upper and lower wall members 12 and 13, the channels 9and 104 and I-beams11 may be rigidly secured together by any suitablemeans, such as Welding or the like. Specifically, the upper member 12 isformed to dene the guideways 2 and 3, said guideways each having agenerally horizontally disposed bottom wall 15 and laterally spaced sidewalls 16, the side walls 16 of each guideway being disposed in planeswhich converge upwardly, see particularly FIGS. 2 and 5-8. Air in theduct 8 is maintained under predetermined pressure by blowers or the like17 having their outlet portions connected at spaced intervals along theright-of-way 1 by conduits or the like 18, the blowers 17 being drivenby suitable and well-known means, not shown. tion is had between theduct 8 and guideways 2 and 3 by conduit portions in the nature ofdownwardly deformed portions -19 which define jet openings 20 in thebottom walls 15, of the guideways 2 and 3, and which direct air underpressure from the duct 8 angularly upwardly and forwardly in thedirection of desired travel of vehicles disposed in the guideways 2 and3.

For the purpose of the present example, a preferred form of vehicle isshown in FIGS. 2, 5-7, 12, 1926 and 36, and is indicated in its entiretyby the reference numeral 21. It will be understood that as many vehicles21- as required for adequate ytransportation will be provided in a givensystem, two thereof being shown fragmentarily in FIGS. 26 and 36.Preferably, the vehicles are generally rectangular, the vehicle shownbeing in the nature of a passenger conveyance having a plurality ofpassenger seats 22 therein, each seat preferably having capacity for onepassenger. Such an arrangement permits the use of a vehicle which isquite narrow with a minimum of frontal area and providing a minimum windresistance when the vehicle is in motion. The body of the yvehicle 21comprises a bottom wall 23, opposed sides 24 and 25, the former of whichis equipped with windows 26 and the latter of which is providedwithwindow-equipped doors 27, one adjacent each seat 22, a top wall 28, andfront and rear Walls 29 and 3Q` respectively. In the form of vehicleshown, access is had to a baggage compartment 31 rearwardly of therearmost seat 22-by-a door 32, and the front wall 29 is providedwith aconventional windshield 33 of glass or other transparent material.

The front, rear and side walls of the vehiclep2-1 extend below the levelof the bottom wall 23 thereof, and, togethcr with the bottom wall orfloor 23, are reinforced by a peripheral frame 34preferably made fromstructural channel members or the like. The bottom wall 23 and frame 344cooperate with the underlyingportion of the bottom guideway Wall 15 todefine a plenum 35 that is divided intoa plurality of compartments 36 byvertically disposed longitudinal and transverse'partition elements 37and 38V respectively, said partition elements being welded or otherwiserigidly secured to the bottom wall 23 and frame 34. Elongated skids orbrake shoes 39. lof suitable material are bonded or otherwise rigidlysecured to the bottom surface 4t) of opposite side portions of theyframe 34 for engagement with the guideway bottom wall 15, as willhereinafter become apparent. The bottom wall 23 is provided with aplurality of air inlet openings.

41, the top wall 28fhaving air outlet openings 42 therein which underliea hood or the like 43 which, if desired, houses a porous filter element44. t will be here noted that the top Wall 28 may, if desired, comprisea plurality of panelsd of rigid transparent or translucent material fortransmission of light from the exterior of the vehicle 2.1 to theinterior thereof, in cooperation with the windows in the front and sidewalls of the vehicle 21. It will be noted that a small amount ofthe airunder pressure introduced to the plenum35 from the duct S-through thejet Communicaaafla, 876

openings Ztl, will be forced upwardly through the inlet openings 41 tothe interior of the vehicle 21 to ventilate the same, the aircirculating upwardly through the interior of the vehicle and escapingoutwardly through the outlet openings 42. f Assuming that air in theduct 8 is substantially at atmospheric pressure, the vehicle 21 will bestationary, the skids or shoes 39 resting on the guideway bottom wall15. Energization of the blowers or compressors 17 raises the pressure ofair in the duct 8 and plenum 35 to levitate the vehicle 21. The deformedportions 19 of the guideway bottom wall 15, defining the jet openings20, are so angularly displaced from the generally horizontal plane ofthe guideway bottom wall 15, that the jets of air moving through the jetopenings Ztl impart propelling force to the Vehiclef21 .in a forwarddirection longitudinally of the guideway in which the vehicle isdisposed. By dividing the plenum into a series of longitudinally spacedcompartments, with the use of the transverse partition elements 38,longitudinal pitch stability of the vehicle is achieved. Should one endof the vehicle be more heavily loaded than the other end, a pressurebuild-up will occur at the loaded end due to the fact that escape of airfrom the plenum compartments 36 at the more heavily loaded end of thevehicle is not as rapid as that at the opposite end. This pressurebuildup at the loaded end will tend to raise the loaded end of thevehicle, and a condition of fore and aft stability will be reached. Itwill be appreciated that a non-uniformly loaded vehicle will always tendto slope downwardly toward the loaded end thereof. However, by utilizingthe transverse partitions 33, this slope is minimized. In like manner,the longitudinal partitions 37 aid materially in achieving rollstability in the vehicle. The guideways Z and 3, being wider at theirbottom portions than at the top portions thereof by virtue of theupwardly and inwardly sloping side walls 16, permit limited roll of thevehicle on its longitudinal axis. However, should the vehicle begin toroll on its longitudinal axis in one direction or the other laterally ofthe line of travel, the plenum compartments 36 at one side of thelongitudinal partitions 37 raise relative to the plenum compartments 36at the opposite side of the partitions 37, creating a pressuredifferential therebetween. This raising of the compartments 36 at saidone side of the partitions 37 causes a rise in pressure in the spacebetween the adjacent side wall 16 of the track and the raised side ofthe vehicle plenum portion; and this rise in pressure, together withsaid pressure differential between the plenum compartments at oppositesides of the longitudinal partitions 37 immediately rolls the vehicleback to a state of equilibrium. Yaw, or lateral sway, is held to aminimum and quickly eliminated by the pressure of air in the spaces 16'between the sides of the plenum and the adjacent side walls 16 of theguideway. Should yaw, or turning of the vehicle on a vertical axis,occur, a differential in pressure is created in the spaces 16 betweenthe front and rear end portions of the vehicle. The tendency of thepressure to be equalized over the length of the vehicle causes thevehicle to immediately center itself in the guideway and to establishand hold a parallel relationship therewith. For the purpose ofminimizing frictional contact between the sides of the vehicle and theupper side portions of the side walls 16 of the guideways, the guidewaysmay be super elevated or banked as is common practice with highways andrailroad beds. Further, if desired, the vehicle or vehicles 21 may beprovided with skids or slippers, not shown, at -the opposite sidesthereof for engagement with the upper portions of the guideway sidewalls 16 to limit yaw or lateral movement of the vehicle in theguideway.

Assuming that air is delivered from the compressors 17 to the duct 8 ata constant volume and pressure, 'and that all of the vehicles 21traveling in the guideways 2 and 3 are of substantially the same weight,the vehicles will travel in the guideways at substantially equal speeds.Hence, in order that any given vehicle might be brought to a stop at agiven station area 4 without being struck by a succeeding vehicle, thedeceleration areas 6 are laterally offset from their respective mainline guideways 2 and 3 and include extraction area portions 46 which areextensions of the deceleration areas 6, see FIGS. l, 3, 6, 10, and ll.At the deceleration area portions 46, the width of the guideways 2 and 3is increased to slightly more than twice the normal width thereof, andthe bottom guideway wall is `formed to provide jet openings 47 which aredisposed to direct jets of air transversely away from the main line ofthe guideways 2 and 3, as shown by arrows in FIGS. Sand 6. As shown, theopenings 47 are disposed in a row that extends at an oblique angle tothe row of jet openings 20 toward the deceleration areas 6 and stationarea 4. It will be noted, with reference to FIGS. 1 and 3, that theouter side walls of the guide tracks 2 and 3 are removed at theextraction portions of their respective deceleration areas to permitlateral displace-ment of the vehicles 21. The deceleration areas 6 andtheir extraction portions 46 are provided with side walls 48 which limitlateral movements of the vehicles 21 in directions away from the mainline of the guideways 2 and 3. It will be further noted, with particularreference to FIGS. 3 and 11 that the jet openings Ztl at the extractionportions 46 are disposed to propel vehicles 21 angularly toward theinner side walls 16 of their respective guideways, to prevent thevehicles from accidentally moving laterally toward the decelerationareas when it is desired to by-pass the adjacent station area 4. At theextraction portions 46, the guideway bottom walls are provided with jetopenings 49 that are disposed to propel vehicles 21 angularly towardengagement with the side walls 48, the deceleration areas having otherjet openings 50 that direct air to the deceleration areas longitudinallytoward their respective station areas 4. It will be noted that the jetopenings 50 are spaced progressively further apart from the extractionareas 46 toward their respective station areas 4, whereby the flow ofair to the plenums 35 is progressively reduced until levitation of thevehicles ceases, and engagement of the bottom guideway wall 15 in thedeceleration area 6 by the brake shoes or skids 39 causes the vehicle 21to stop at the station area 4.

-v If desired, some or all of the jets 50 may be disposed to levitatethe vehicles only, without imparting forward movement thereto, so thatthe vehicles may coast on a cushion of air until reaching the stationarea. Further, if desired, provision may be made for excess thrust inthe extraction jets through the jet openings 47 to move the vehicles 21and hold the same positively against the curb or side walls 48.

The jet openings 47 are normally closed by suitable valve means which,in the embodiment shown, comprise valve blocks 51 mounted on anelongated beam 52 which underlies the bottom wall 15 of the extractionportion of the deceleration area 6. The beam 52 is mounted on aplurality of vertically disposed guide rods 53 and yieldingly urged in adirection to cause closing of the jet openings 47 by coil compressionsprings or the like 54, see particularly FIG. l0. Mechanism for movingthe valve block elements 51 toward a valve open position against bias ofthe springs 54 involves a lever 55 that is pivotally mountedintermediate its ends to a supporting bracket 56 and which has a pin andslot connection 57 at one end with lthe beam 52, see particularly FIG.6. The opposite end of the lever 5S hasa pin and slot connection 58 witha second lever 59 pivotally connected at its intermediate portion to asupporting bracket or the like 60, the opposite end 61 of the lever 59being adapted to be connected to suitable operating mechanism, notshown, for imparting valve opening movements to the lever 59. In theembodiment shown in FIGS. l, 3 and 6, the outer end portion 61 of thelever 59 is provided with a button, treadle or the like 62 for manualoperation, if desired. While but a single set of valve blo'ck` elements51, mounting beam 52 therefor, and operating mechanism is shown in FIGS.6, l and 1l, it wiil be understood that the extraction portions of bothdeceleration areas are provided with such valve block elements andoperating vmechanism therefor. Thus, when it is desired to bring a givenvehicle into a given station area, it is only necessary that theappropriate button 62 be depressed and held depressed until the vehiclehas been shifted away `from the main line, after which the button isimmediately released to permit a following vehicle to continue along themain line of its respective guideway 2 or 3.

Each acceleration area 5 includes a vehicle insertion area portion 63that is similar to but substantially a reversal of the extractionportions 46 of the deceleration areas 6. As shown in FIGS. 1 and 4, aportion of the outer guideway side wall 16 is removed and the bottomguide wall is laterally extended to an outer side Wall 64. Also, as withthe extraction section, the jet openings 20 in the insertion portion ofthe acceleration area are disposed to direct air under pressure from theunderlying duct 8 toward the inner side wall 16 of the main line of theguideways 2 and 3. The guideway bottom wall in the acceleration area isformed to provide jet openings 65 that are spaced relatively closely,together whereby to ac'- celerate movement of a vehicle leaving theadjacent station area 4 to the normal speed of vehicle travel beforeinsertion is made thereof to the main line of travel. At the insertionportion 63, the guideway bottom wall 15 is provided with a plurality ofjet openings 66 disposed in a row extending obliquely from theacceleration area adjacent the station area toward the main line oftravel in the adjacent guideway 2 or 3, the jet openings 66 beingdisposed to direct tlow of air transversely toward said main line oftravel, as indicated by arrows in FIGS'. 4 and 7. As shown in FIG. 7,flow of air through the insertion jet openings 66 is controlled by aplurality of Valve elements 67, one for each of the jet openings 66. ThevalveA elements 67 are carried by an elongated beam 68 mounted onvertically disposed rodsy 69 and yieldingl'y urged toward a closedposition by springs 70. The beam 68 is moved toward a valve openposition by mechanism identical to that associated with the valvecarrying beam 52, the parts thereof being identified by referencecharacters identifying like parts in FIG. 6.

When a given vehicle 21 is caused to be propelled to a station area 4,it cornes to rest at its respective loading platform 7 for unloading ofpassengers'or freight, and for reloading for transit to the nextdestination. Means for moving the vehicle from the station area 4 'tothe pneumatically operated acceleration area 5 comprises a plurality ofrollers or the like 68 shown diagrammatically in FIG. 1. Preferably, therollers 68' are power driven by suitable means, not shown, and are heldagainst rotation by conventional braking means such as brake shoes orthe like, not shown, when a vehicle thereon is at rest in the stationarea. Then, when it is desired to move the vehicle from the station areato the ypneumatic system, the rollers 68' are caused to rotate in thedesired direction to move the vehicle on to the acceleration area.Obviously, a vehicle should not be moved from'the station area 4 to theacceleration area 5 until an adequate space between vehicles on a givenone of the guideways 2 and 3 exists. Should a vehicle at the stationarea 4 be inadvertently propelled from the station area on to theacceleration area 5 when insutlicient spacing exists between a pair ofvehicles approaching on the adjacent main line, the valve elements 67will not be opened by the operator or operating mechanism, and ythevehicle on the acceleration area 5 will be caused to travel along thelside wall 64 and into a fail safe area 69, see FIGS. l and4. The

fail safe area 69 is similar to the guideways 2 and 3, the bottom wall 70 thereof being an extension of the wall 15 of the acceleration area 5,and having jet openings 7 0 that are progressively spaced further apartlongitudinally outwardly from the insertion portion of the accelerationarea, whereby to gradually decrease the volume of air under the vehiclethereon so that the skids 39 engage the bottom wall '70 and the vehicleslides gradually to a stop at a portion of the fail safe area having nojet openings. As shown in FIG. 4, jet openings 65 at the insertionportion of the acceleration area 5 are disposed to direct flow of airangularly toward the outer side wall 64 to prevent accidental insertionof the vehicle into the main line. Suitable means, not shown, will beutilized to return the vehicle to the adjacent station area 4 forreinsertion into the system. With this arrangement, collision withvehicles on the main line of the guideways 2 and 3 is avoided.

Means for locking each vehicle door 27 and 32, and for aiding in openingand closing of said doors, are shown in FIGS. 19-25, reference being hadthereto. Each door 27 and 32 is rigidly mounted on a different one of aplurality of hinge pintles 71 by means of a pair of hinge elements '72rigidly secured to the pintles 71 and to respective ones of the doors 27and 32. As shown particularly in FIG. 21, the hinge elements 72 engagethe upper ends of cooperating hinge element-s 73 in which the pintles 71are journalled, the hinge elements 73 being rigidly mounted to adjacentportions of the side wall`25 of the vehicle 21, by mounting screws orthe like 74, see FIG. 24. The several doors 27 and 32 are provided withconventional latch means, not shown, for releasably holding the doorsclosed, the latch means including the usual inner and outer latchhandles 75, the outer ones of which are shown in FIGS. 2 and 36.

Each door 27 and 32 is provided in its bottom portion with an aperture76 that is aligned with a cooperating one of a plurality of apertures 77in the bottom wall 23 and frame 34 of the vehicle, when the door isclosed. A plurality of locking pins 78 are disposed one each inunderlying axial alignment with a different one of the apertures '77,one of which is shown in FIG. 23. Each locking pin 78 extends axiallyupwardly from a cooperating piston 79 that is received in a cylindricalelement 8? welded or otherwise rigidly secured to the interior surfaceof the frame 34, each of said cylindrical elements 86 being providedwith openings 81 in the bottom walls thereof. Coil compression springs82 are interposed between the pistons 79 and the upper ends of theirrespective cylindrical elements 8@ to yieldingly urge their respectivelocking pins 78 away from their cooperating apertures 77 and 76, wherebyto permit their respective doors 27 and 32 to be opened. When a vehicle11; is disposed in overlying relationship to one or more of any of thejet openings, air under pressure within the plenum 35 imparts upwardmovement to each of the pistons 79, against yielding bias of the springs82, to move the locking pins 7S into cooperating aligned apertures 77and 76 to rigidly lock the doors 27 and 32 against opening movementswhile the vehicle is in transit. Obviously, when the pressure within theplenum 35 is sufficiently reduced, as when the vehicle is disposed in astation area, the springs S2 will cause the locking pins 78 to beretracted from the apertures 76 and 77, permitting opening of the doors27 and 32.

Rigidly secured to the lower end of each pintle 7l for common pivotalmovements therewith is one of a plurality of bifurcated crank arms S3that have pin and slot connections 84 with individual sleeves or collars85 axialiy slidably mounted on an elongated shaft 86, see particularlyFIGS. 19-21 and 25. The shaft 86 extends longitudinally of the plenum'35and is mounted for longitudinal sliding movements in brackets or thelike 87 welded or otherwise rigidly secured to the bottom wall 23 of thevehicle 21. A plurality of abutment collars or the like S8 are rigidlysecured to vthe shaft 86 in axiallyspaced relations'hip, and co'ilcompression springs 89 and 90 are arranged incooperating pairs on theshaft 86. The arrangement is such that each spring 89 is interposedbetween a different one of the sleeves 85 and an adjacent bracket 87,whereas each of the springs 90 is interposed between a different one ofthe sleeves 85 and one of the abutment collars 88, the springs 89 and 90loosely encompassing the shaft 86. Preferably, the springs 90 areheavier than the springs 89 and exert greater force when compressed.Further, when the doors 27 and 32 are closed, and the shaft 86 moved toits limit of movement in a direction to the right with respect to FIGS.19 and 20, the springs 89 are in a lightly compressed condition, whereasthe springs 90 are in a substantially neutral state. Movement of theshaft 86 to the left with respect to FIGS. 19 and 20 causes the springs90 to be compressed to urge the 4doors 27 and 32 in a door-openingdirection. Hence, when a given door latch is released, its respectivedoor 27 or 32 will automatically` open to an extent wherein itsrespective springs89 and 90reach a state of equilibrium. 1referably,whenthis state of equilibrium is reached, the respective door 27 or 32will be substantially fully open. It will be appreciated that,the-sleeves or collars 85 being slidable on the shaft 86, the lshaft 86does not exert a positive-opening force against the unlatched door, butonly a yielding force thereagainst. y Hence, should an obstruction, suchas a person, be standing just outside the door during opening thereof,the likelihood of injury to the person or to the door is minimized. Withone or more of the doors 27 and 32 open, movement of the shaft 86 to theright with respect to FIGS. 19 and Z0 will release pressure of thecollars 88 against their respective springs 90 and permit the springs 89 to bias the doors 27 in a doorclosing direction. The yielding forceexerted by the springs 89 is suchthat injury to a person or object inthe path of closing movements of an open door 27 or 32 and struckthereby is also minimized.

Means for imparting longitudinal movements to the shaft 86 in oppositedirections, is shown in FIGS. 19, 20 and 22, and comprises a shiftercollar 91 fast on the shaft 86 and having a rigid arm 92 projectinglaterally outwardly therefrom, a coil compression spring 93 interposedbetween the collar 91 and an adjacent one of the brackets 87 toyieldingly urge the shaft in one direction of its longitudinal movement,and other mechanism now to be described. The outer end of the arm 92 ispivotally connected to one end of one Aofa pair ofl toggle links 94 and95, as indicatediat 96, see particularly FIG. 22. One end of the otherof the toggle links 94 and 95 is pivotally connected to a bracket 97that is rigidly secured to the bottom vehicle wall 23, and the adjacentends of the toggle links 94 and 95 are pivotally connected together by apivot shaft or the like 9S in which is journalled a roller 99. Theroller'99 is adapted to be engaged by -a plate-like actuator 100 mountedon the upper end of-a push rod 101 for vertical movements. Upwardmovement of 'the push rod 101 and actuator plate 100 imparts movement tothe toggle links 94 and 95 in a direction to move the shaft 86 againstbias of the spring 93 to cause the doors 27 and 32 to be yieldinglyurged toward their open positions. The push rod 1 may be assumed to bevertically moved by any suitable operating means, not shown, and it willbe appreciated that a separate push rod 101 and actuator plate thereforis provided adjacent each loading platform 7. Inasmuch as the operatingmechanism for the push rod 101 does not, in and of itself, comprise theinstant invention, showing and description thereof is omitted, in theinterest of brevity.

It will be appreciated that a commercial embodiment of the system'herein disclosed may involve many miles of guideway and air duct with acorrespondingly vast number of jet openings between the duct andoverlying guideways. The use of the jet openings as above described,obviously results in the movement of a great deal of air under pressure,a greater part of which is wasted. Hence, 1 provide each jet opening inthe guideways 2 and 3, as well as in the portion of the acceleration anddeceleration areas 5 and 6 and fail-safe areas 69 with automatic valvemeans, now to be described. Referring to FIGS. 26-33, 35 and 36, it Willbe seen that the bottom guideway walls 15 thereof are provided with jetopenings 102 which comprise a portion of the conduit means for theguideways as do valves underlying each of the openings 102 said valvesbeing indicated in their entireties by the reference numeral 103. Thevalves 103, being identical, but one thereof will be described indetail. The valve 103 comprises a frame-like valve body having opposedside walls 104, a valve seat 105 extending between the side walls 104 atone end portion thereof, a cross member 106 at the opposite end of theside walls 104, and a transverse stop bar 107 in laterally spacedrelationship to the valve seat portion 105. A valve element 108, in thenature of a leaf spring, is anchored at one end in the cross member 106,the opposite end portion thereof being movable between the transversestop member or bar 107 and the overlying valve seat portion 105. Thevalve 103 is rigidly secured to the bottom guideway wall 15 by screws orthe like 109 screw threaded into the cross member 106 and valve seatportion 105, see particularly FIGS. 27 and 29. The valve element 108 isso formed and anchored as to be yieldingly urged toward engagement ofits free end with the transverse stop bar 107, and is closed by thedifferential in air pressure between the duct 8 and the space above theguideway bottom walls 15. When a vehicle 21 passes over the valve 103,the air pressure within the plenum 35, being greater than atmosphericpressure, permits the valve element 108 to move toward its valve openposition, as shown by the full lines and lower dotted lines in FIG. 33.The extent to which the valve element 108 moves toward the stop bar 107is determined by the pressure differential between the duct 8 andoverlyin-g plenum 35. It will be noted that the valve engaging seat 105and the valve element 108, in its open position, slope upwardly andforwardly in the direction of movement of the vehicle 21, whereby todirect air under pressure from the duct 8 to the plenum 35 in directionsto levitate and propel the vehicle 21 forwardly in the guideways 2 and3. As the vehicle moves forwardly away from overlying relationship tothe valve 103, the higher pressure differential is immediately restored,moving the valve element 108 upwardly into engagement with itscooperating valve seat 105 to close the valve. Thus, as the vehicle 21moves along its guideway 2 or 3, the valves 103 open in succesf sion asthe vehicle moves thereover and close in succession immediately as thevehicle leaves the space thereabove.

A modified form of the valve 103 is shown in FIG. 34, and is indicatedin its entirety by the numeral 110. The valve 110 comprises a valve bodyhaving opposed side walls 111, one of which is shown, a cross member 112at one end, a valve seat 113 at the opposite end, and a transverse stopbar 114 in underlying spaced relation to the valve seat 113. A leafspring Valve element 115, similar to the valve element 108, isyieldingly urged toward a closed position in engagement with the valveseat 113, and Vis moved to its open position against the stop bar 114 bya conventional solenoid 116. The solenoid 116 may be assumed to beconnected in a. suitable control circuit, not shown, the control circuitnot forming a part'of the instant invention. Preferably, a plurality ofthe valves 110 are used at the beginning of the acceleration areas 5 toinitially pressurize the plenum 35 of each vehicle 21 as the vehicle ismoved away from the station area. Further, and if desired, a pluralityof valves 110 may be substituted for the valve block elements 51 andvalve elements 67 and valve operating means therefor, to cause vehiclesto be shifted from the main guideways 2 and 3 to the deceleration areasand from the acceleration areas to the guideways 2 and 3.

In any rapid transit system involving the use of a plurality of vehiclesor groups thereof on a single track or guideway, it is highly importantthat a minimum distance be maintained between said vehicles or groupsthereof. This is particularly important in the system of the presentinvention in which the vehicles themselves are devoid of independentcontrols for the operation thereof. A minimum spacing between a pair ofvehicles on the same guideway must be maintained for safety reasons aswell as to give a leading vehicle suicient time to be shifted from themain right-of-way to the deceleration area, and to re-close the valvesgoverning the shifting of the lead vehicle before a following vehiclereaches the shifting jets-assuming of course, that it is desired thatthe following vehicle proceed on the ri-ght-'of-way to a differentstation. A preferred means for maintaining a given longitudinally spacedrelationship between a pair of adjacent vehicles moving along one of theguideways 2 or 3 is shown in FIGS. 27-34 and involves valve lockingmeans associated with each of the valves 103. and, if desired, thevalves 119. Each valve 103 is provided with a bracket 117 in which ispivotally mounted a valvel engaging latch member 118, by means of apivot pin or the like 119. A latch actuator 120 is pivotally mounted atone end to the pivot pin 119 and is provided with a latch-engaging bar121 that is operative to move the latch member 118 in a valve releasingdirection responsive to yswinging movement of the latch actuator 120 inone direction about the axis of the pivot pin 119. A torsion spring 122has oppositeends engaging the latch member 118 and actuator 12) andyieldingly urges the latch member 118 toward engagement with the valve108 and with the latch engaging bar 121. The opposite or free end of thelatch actuator 12) is connected to a piston 123 by means of a rigid link124, the piston 123 being mounted in a cylinder 125 that is rigidlysecured to the bracket 117. The link 124 extends into the cylinder 125through an enlarged opening 126 in one end of the cylinder 125, theopposite end of the cylinder being substantially closed by the bracket117 except for a relatively large opening 127 and a relatively smallopening 128 through the cylinder end wall forming portion of the bracket117. The relatively large opening 127 is normally closed by a springpressed ball check valve 129, see FIGS. 32 and 33. The piston 123 isyieldingly urged in a direction to move the latch element 113 out ofengagement with the valve element 108 by means of a coil compressionspring 130. With reference to FIG. 32, it will be seen that, when thepiston 123 is moved by the spring 130 to the kend of the cylinder 125containing the large opening 126, the latch element 118 is disposed outof engagement with the adjacent end of the valve element 168. Duringdownward opening movement of the latch element 108, the end thereofengages a cam surface or edge portion 131 of the latch actuator 120 andmoves the same and the latch element 118 to their positions shown inFIG. 33. Air in the cylinder 125 between the piston 123 and the end walldefined by the bracket 117 is forced outwardly through the largerpassage 127 and check valve 129 at a relatively rapid rate. Duringclos-ing movement of the valve element 1113, the free en-d thereofengages the front surface or edge 132 of the latch element 118 and camsthe same rearwardly against bias of the torsion spring 122. When thelatch element 103 reaches its closed position shown by the upper dottedlines in FIG. 33, the latch element 11S is yieldingly urged intolatching engagement therewith by the torsion spring 122. During closingand latching of the valve element 108, the spring 131) moves the piston123 toward its position of FIG. 32 the piston moving realtively slowlydue to the relatively slow inow of air to the cylinder 12S through therestricted opening 123. Thus, the valve 108 is locked in a closedposition for the time interval required for movement of the piston 123from its position of FIG. 33 to its position of FIG. 32, the cylinder125 andgpiston 123 acting in the manner of a conventional dashpot.

Assuming that the rate of travel of the vehicle 21 in the guideways 2and 3 is substantially 45 miles per hour or 62 feet per second, and thata minimum distance between said ve'hicle and a following Vehicle is 26feet, the relatively small opening 128 is so restrictedthat air will beadmitted to the interior of the cylinder 125 at a rate which willrequire .4 of one second `for the piston 123 to move from its positionof FIG. 33 to its valve element releasing position of FIG. 32. I Hence,should the distance between a pair of traveling vehicles 21 become lessthan the minimum of 26 feet, the valve element y108 will be heldaga-inst opening when the kfollowing vehicle moves thereover, until thelatch element 118 is moved out of engagement with the valve element 108.Thus, the supply of levitating and propelling air to the v,followingvehicle is lessened, causing theH followingkvehicle to decelerate untilthe minimum spacing therebetween and the preceding vehicle 21 isreached. It will -be noted that, duringmovement of lthe latch actuator120 .from its position of FIG. 33 to its position of FIG. 32, the, latchengaging bar 121 engages the latch element 118 tovmove the same out ofengagement with the valvewelement108-`lIt will be further appreciatedthat, inasmuch as a plurality of valves 103 underlie a vehicle 21 at anygiven time, lthe vehicle m-ay be decelerated by means of delayedopeningdof the valves 103 until the desired vehicle spacing is achieved,without appreciable loss in levitation of the vehicles.

FIGS. and 36 show the right-of-way 1 Y as beingy enclosed by anelongated housingy or the like 133 which overlies the guideways 2 and 3to protect the guideways 2 and 3 from the elements, and the vehicles 2 1from ythe elfects of crosswinds and the like.' Further, to eliminateturbulence within the housing 123, caused by the passing of one vehicle21 by another thereof moving in the opposite direction on the adjacentguideway, I provide a generally vertically disposed partition 13 4 thatextends longitudinally of the right of way. In order to provideillumination for the passengers in the vvehicles 21, I provideconventional tubular lamps 135 that extend longitudinally of theright-of-way and which may be assumed to be disposed at desired spaceintervals longitudinally within the housing 133. With this arrangement,it is unnecessary to provide the housing 133 with windows or the likefor illumination. y

By providing the housing 133, the air used to levitate and propel thevehicles 21 along their respective guideways 2 and 3 may be returnedtothe blowers 17 by means of return ducts 136. If desired, the ducts 136mayjbe provided with valves 137 for controllingV the percentage o-f airexhausted from within the housing 133 and returned to the fan y17. Thevalve or damper 137 may be moved to direct all of the air exhausted fromwithin the housing 133 to the fan 17 or, selectively/,to direct all orany portion of the exhausted air lthrough. an outlet 13S to atmosphere.For colder weather, suitable` heating means, not shown, may be utilizedin theblower system, to supply warm air to the enclosed right-of-way 1.When heated air is required, .the damper or dampers 137Vwill preferablybe moved to close vthe outlet 138 and permit re-circulation of theheated air through the entire system. It will be noted, with referenceto FIGS. .35 and 36, that the blower 17 is provided with a second inletopening 139 which may be partially or wholly closed by wellfknown means,not shown, preferably in cooperation with opening and closing movementsof the valve or damper 137, to properly regulate the relative quantitiesof fresh and recirculated air through the system.

As shown in FIGS. 35 and 36, the entire structure may be elevated fromground level and supported by means of suitable pillars or likesupporting structure 140 or, if desired, the system may be disposed atground level, with the lower duct forming member`v13` resting on theground.

or on a suitable foundation. It will be further appreciated,

'13 las above mentioned, that the entire right-of-way may be produced asan underground installation, as conditions require.

As shown in FIGS. 14-18, the plenum of a 'given vehicle 2,1 may beproduced in various shapes. In the modified form shown in FIGS. 14 and15, the vehicle is indicated generally at 21', said vehicle 21 having apair of longitudinally spaced frames 141 journalled in wearing plates orthe like 142, as indicated at 143 for pivotal movements on verticalaxes. The frames 141 are provided with skid rails 144 and define plenums145 that lare divided into plenum compartments 146 by longitudinal andtransverse partitions 147 land 148 respectively, similar to thepartitions 37 and 38 respective-ly. The use of a pair of plenums of thetype shown in FIGS. 14 and l5, pivotally secured tothe vehicle 21',permits a guideway to be curved on a shorter radius than is possiblewith the use of a substantially longer plenum such as the plenum 35. Inother words, the arrangement .illustrated in FIGS. 14 and l5is'analogous to -the articulated wheel mounting arrangement of railroadvehicles and the like.

' In the further modified larrangement illustrated more or lessdiagrammatically in FIGS. 16 and 17, a vehicle 149 is provided atitsbottom with a pair of generally cylindrical lframes 150 disposed inspaced relationship longitudinally of the vehicle 149 and defining apair of plenums 1.51. A pair of laterally spaced reversely curved yframewalls 152 cooperates with the frames 150 todefine a :central plenum 153.This arrangement -is suitable for vehicles of relatively shorter lengthwith respect to the width thereof than the vehicles 21 and 21.' andprovides Ifor an optimum plenum area consistent with the ability of thevehicles to negotiate guideway curves of relatively short radius. A

In Vth'emodified yform shown in FIG. 18, a vehicle 154, shown in endelevation, is provided with a plenum defining frame 155 that is' ofgreater width than the Ibody of the vehicle 154 thereabove. Preferably,this type of vehicle is used for thepurpose of conveying heavy freight,where a maximum` plenum area is required.

An alternative arrangement for maintaining a predetermined minimumdistance between vehicles on a given guideway is shown diagrammaticallyin FIG. 37 and involves a, pneumatic interlock system. A guideway 2a isprovided with a pluralitypof longitudinally spaced valves 103:1 each'of` which is provided, as shown in FIG. 38, with alatoh 156 in the formof a plunger rod secured to apiston 157 that is mounted forreciprocatory movements in a cylinder 158 suitably mounted to theguideway 2a. A c oil compression spring 159 yieldingly urges the piston157 and latch bar or element 156 out of latching engagement With theadjacent valve element 103e. An air tube 160 extendsfrorn the outer endof the cylinder 158 longitudinally of the guideway 2a and in thedirection of forward movement of a vehicle in the guideway, apredetermined distance, the opposite end of the air tube 1 60communicating with the guideway 2a as indicated at161. As shown in FIG.37, the air tubes 161) exten-d equal distances longitudinally of theguideway 2a and, as avehicle passes over or by a tube end 161 or groupthereof, the pressure of air in the plenum causes a corresponding valveelement 108eV rearwardly of the vehicle to be locked closed by pressureof air against its respective piston 157. Themas the vehicle movesbeyond said given tubey end 1,61', air pressure within the air tube 16)is automatically released, and the spring 159 of the correspondingcylinder S causes yretraction of the locking element 156 to permit thevalve element 103:1 to open responsive to passage' of a vehicle'thereoven In the modified forms shown in FIGS. 39 and 40, a guideway`2b'is shown as comprising a bottom wall 15b and opposed vertical sidewalls 162. In FIG. 39, a ve hicle 21b is lshown as being provided with aplenum 35h having downwardly converging side walls 163. In FIG. 40, avehicle 21C identical to the vehicle 21, is provided 14 withlongitudinally extending flanges 164 that project laterally outwardlytoward adjacent side walls 162. In FIG. 4l, a vehicle 21 is shown asbeing disposed in a guideway 2c, this guideway having a bottom wall 15cand laterally spaced vertical side walls. 165. A pair of longitudinally`extending flanges 166 adjacent the upper edges of the side wallsproject laterally inwardly toward the adjacent sides of the Vehicle 21.The arrangements shown in FIGS. 39-40 and 4l have substantially the sameoperating characteristics as that illustrated in FIGS. 2, 5-8 andothers.

It will be appreciated that, While I have shown a vehicle as having aplurality of single seats in tandem, the present invention contemplatesguideways which can accommodate cars having double seats, seats onopposite sides of a central aisle, or any desired seating arrangement.

While I have shown anddescribed a preferred embodiment of mytransportation system, and several modified forms of various componentsthereof, it will be understood that the same is capable of furthermodification, and that modication may be made without departure of thespirit and scope of the invention as defined in the claims. v

What is claimed is:

1. A pneumatic propulsion transportation system comprising:

(a) means including a generally horizontal wall p0rtion and generallyopposed wall portions angularly displaced from said generally horizontalwall portion and defining an elongated upwardly opening guide- Wfy,

(b) a transport vehicle disposed in .overlying relation to saidgenerally horizontal wall portion for movement longitudinally of saidguideway,

(c) said vehicle having a bottom portion in closely spaced relation tosaid generally opposed wall portions and cooperating with said generallyhorizontal wall portion to define a plenum,

(d) conduit means including a duct extending longitudinally of saidguideway, one of said wall portions having a plurality of longitudinallyspaced'openings for communication betweeny said duct ,and guideway, saidconduit means being adapted to lbe connected to a `source of air underpressure and operatively connected to said guideway defining means anddisposed to direct air under pressure to said plenum in al direction tolevitate said vehicle and propel said vehicle in one directionlongitudinally of said guideway,

(e) a plurality of normally closed valves' e'ach individual to adifferent one of said longitudinally spaced openings and each arrangedtoopen when disposed directly below said vehicle and to close responsiveto movement of said vehicle away therefrom longitudinally of saidguideway,

(f) and time delay devices operatively associated with each of saidvalves to hold said valves closed for a predetermined time intervalafter closing thereof.

2. A pneumatic propulsion transportation systemcomprising:

(a) wall structure defining, an elongated cross sectionally generallyU-shaped guideway having opposed side walls disposed in planes whichconverge in an upward direction and a generally horizontal bottoni wall,and a longitudinally extending air duct underlying said guideway,

(b) a transport vehicle having a bottom portion disf posed in saidguideway for movement of said vehicle longitudinally of said guideway,

(c) said vehicle bo'ttom'portion cooperating with wall portions of saidguideway to define a plenum,

(d) and means for supplying air under pressure to said duct,

prising:

(a) means defining an upwardly opening guideway having a generallyhorizontal bottom wall and laterally spaced side wall portionsprojecting upwardly from said bottom wall,

(b) a transport vehicle disposed in overlying relation to saidbottomwall for movement longitudinally of said guideway,

(c) Said vehicle havingl a bottom portion cooperating with theunderlying portion of said guideway to define a plenum,

(d) conduit means adapted to be connected to a source of air underpressure and operatively connected to said guideway defining means anddisposed to direct air under pressure to said plenum in a direction tolevitate said vehicle and propel said Vehicle in one directionlongitudinally of said guideway,

(e) said vehicle including wall structure defining a chamber and adoorway to said chamber,

(f) a door mounted in said doorway for opening and closing movements,

(g) means for opening and closing said door,

(h) and locking mechanism mounted on said vehicle and responsive topredetermine pressure differential between said plenum and said chamberto positively lock said door against opening movements, andresponsivejto a predetermined decrease in said pressure differential torelease said door for opening thereof. l

4. A pneumatic propulsion transportation system cornprising:

(a) means defining an upwardly opening guideway having a generallyhorizontal bottom wall and laterally spaced side wall portions,

(b) a transport vehicle disposed in overlying relationship to saidbottom wall for movement longitudinally of said guideway, k

(c) lsaidvehicle having a ,bottom portion cooperating with theunderlying portion of said guideway to define a plenum,"

(d) an air compressor having air inlet means and air outlet means,

(e) conduit means connected to said air outlet means and extendingthrough said guideway defining means and disposed to direct the iiow ofair from said cornpressor to said plenum in a generally forwarddirection longitudinally of. said guideway to levitate said vehicle`.and propel the vehicle in said forward direction,

(t) elongated wall structure extending longitudinally of said guidewayfor substantially the length thereof and cooperating therewith toprovide a tube through v which saidvehicle travels,

(g) said conduit means further including a conduit section connectingsaid tube with said compressor air inlet means and arranged to deliverair from said tube above said guideway to said compressor.

5. A pneumatic propulsion transportation system comprisin g:

i5 cooperating with said generally horizontal guideway wall portion todefine a plenum,

(d) and conduit means adapted to be connected to a source of air underpressure and operatively connected to said guideway defining means anddisposed to direct air under pressure to said plenum in a direction tolevitate and propel said vehicle in one direction longitudinally of saidguideway.

6. A pneumatic propulsion transportation system comprising:

(a) means defining an upwardly opening guideway having a generallyhorizontal wall and laterally spaced side wall portions projectinggenerally upwardly from said horizontal wall,

(b) a transport Vehicle disposed in overlying spaced relation to saidgenerally horizontal wall for freetioating movement longitudinally ofsaid guideway,

(c) said vehicle having a bottom wall and side wall portions cooperatingwith said generally horizontal wall to define a plenum,

(d) and conduit means adapted to be connected to a source of air underpressure and operatively connected to said guideway defining means anddisposed to direct air under pressure to said plenum in a di-` rectionto levitate said vehicle and propel said vehicle in one directionlongitudinally of said guideway,

(e) said vehicle side wall portions and the adjacent side wall portionsof said guideway cooperating to define air spaces normally of greaterwidth adjacent said horizontal guideway wall than at the top of saidguideway.

7. A pneumatic propulsion transportation system cornprising:

(a) means defining an upwardly opening guideway having a generallyhorizontal wall and laterally spaced side wall portions projectinggenerally upwardly from said horizontal wall,

(b) a transport vehicle disposed in overlying spaced relation to saidgenerally horizontal wall for freefloating movement longitudinally ofsaid guideway,

(c) said vehicle having a bottom wall and side wall portions cooperatingwith said generally horizontal wall to define a plenum,

(d) and conduit means adapted to be connected to a source of air underpressure and operatively connected to said guideway defining means anddisposed to direct air under pressure to said plenum in a direction tolevitate said vehicle and propel said vehicle in one directionlongitudinally of said guideway,

(e) said sidewall portions of one of said guideway and vehicle beingdisposed in planes which converge upwardly with planes in which theadjacent side wall portions of the other of said guideway and vehicleare disposed, whereby to define air spaces therebetween of greater widthadjacent said horizontal guideway wall than at the top of said guideway.

8. The pneumatic propulsion transportation system of claim 7 in whichsaid side wall portions of the vehicle are disposed in upwardlydiverging planes, the side wall portions of said guideway being disposedin substantially vertical planes.

.2, A pneumatic propulsion transportation system cornposing:

(a) means defining an upwardly opening guideway having a generallyhorizontal wall and laterally spaced side wall portions projectinggenerally upwardly from said horizontal wall,

(b) a transport vehicle disposed in overlying spaced relation to saidgenerally horizontal wall for freeoating movement longitudinally of saidguideway,

(c) said vehicle having a bottom walland generally vertical side wallportions cooperating with said generally horizontal wall to define aplenum,

(d) conduit means adaptedto be connected to a source 0f air underpressure and operatively connected to said guideway delining means anddisposed to direct air under pressure to said plenum in a direction tolevitate said vehicle and propel said vehicle in one directionlongitudinally of said guideway,

(e) and a pair of opposed longitudinally extended flanges projectinglaterally from the side wall portions of one of said guideway andvehicle toward the adjacent side wall portions of the other of saidguideway and vehicle adjacent the top of said guideway and cooperatingwith said side wall portions to define air spaces normally of greaterwidth adjacent said horizontal guideway wall than at the top of saidguideway.

10. The structure defined in claim 2 in further combination with aplurality of valves each individual to a different one of saidlongitudinally spaced openings for controlling passage of air underpressure from said duct to said guideway.

11. The structure defined in claim 10 in which said valves include valveelements movable between valve open and valve closed positions andyieldingly biased toward one of said positions and operative responsiveto predetermined pressure differential between said duct and guideway tomove to the other of said positions against the yielding biasappliedthereto.

12. The structure defined in claim 4 in further combination with a valveoperatively associated with said conduit section for controlling flow ofair therethrough to said compressor, said compressor air inlet meansbeing operative to introduce air exterior of said tube to saidcompressor independently of said conduit section.

13. The structure defined in claim 3 in which said vehicle wallstructure has an opening through said bottom portion providingcommunication between said plenum and said chamber, and a second openingfrom said chamber to the exterior of said vehicle remote from theplenum, whereby pressure differential between said plenum and saidchamber and exterior of the vehicle provides a current of air throughsaid openings and said chamber.

14. A pneumatic propulsion transportation system comprising:

(a) wall structure defining a pair of elongated crosssectionallyU-shaped guideways in spaced side by side relationship and each havingopposed side walls and a bottom wall,

(b) said wall structure further defining an air duct underlying saidguideways,

(c) transport vehicles associated with each of said guideways and eachhaving'a bottom portion disposed in a respective one of said guidewaysfor movement of the vehicle longitudinally of said guideways,

(d) each said vehicle bottom portion cooperating with wall portions ofits respective guideway to define a plenum,

(e) means for supplying air under pressure to said duct,

(f) one of the walls of each of said guideways having longitudinallyspaced openings therethrough for directing air from said duct to saidplenum to levitate said vehicle,

(g) the openings associated with one of said guideways being disposed todirect air therethrough to propel the vehicles associated therewith inone direction, said openings associated with the other of said guidewaysbeing disposed to direct air therethrough to propel vehicles associatedtherewith in the opposite direction.

15. The structure defined in claim 14 in further combination withsupport means extending longitudinally of said duct intermediate saidguideways, said support means cooperating with portions of said ductdefining wall structure to support said guideways, said support meansdefining openings for free passage of air between portions of said ductat opposite sides of said support means.

16. A pneumatic propulsion transportation system comprising:

(a) means, including a generally horizontal wall portion and laterallyspaced side wall portions projecting upwardly from said generallyhorizontal wall portion, deining a guideway,

(b) a transport vehicle disposed in overlying relationship to saidgenerally horizontal wall portion for movement longitudinally of saidguideway,

(c) said vehicle having a bottom portion cooperating with the underlyingportion of said guideway to define a plenum,

(d) means defining a second guideway laterally displaced from said irstmentioned guideway and in operative connection therewith,

(e) conduit means adapted to be connected to a source of air underpressure and operatively connected to said guideway dening means andincluding conduit sections disposed to direct air under pressure to saidguideways and into said plenum to levitate said vehicle an-d propel saidvehicle in one direction longitudinally of said guideways,

(f) and means for shifting said vehicle from one of said guideways tothe other of said guideways.

17. The structure defined in claim 16 in which said means for shiftingsaid vehicle comprises:

(a) other conduit sections disposed to direct air under pressure to saidguideways in a direction generally away from one of said guidewaystoward the other of said guideways,

(b) and valve means for controlling passage of air through said otherconduit means.

1S. The structure defined in claim 16 in which said conduit sectionsassociated with said second guideway are disposed in spaced relationshiplongitudinally of said second guideway, the spacing between adjacentconduit sections in the second guideway being progressively greater inone direction longitudinally of said second guideway.

i9. A pneumatic propulsion transportation system comprising:

(a) means defining an elongated guideway having a generally horizontalwall portion and laterally spaced side wall portions projecting upwardlyfrom said generally horizontal wall portion,

(b) a transport vehicle disposed in overlying relationship to saidgenerally horizontal wall portion for movement longitudinally of saidguideway,

(c) said vehicle having a bottom portion cooperating with the underlyingportion of said guideway to define a plenum,

(d) means defining a station area laterally displaced from said guidewayand in operative communication therewith,

(e) conduit means adapted to be connected to a source of .air underpressure and operatively connected to said guideway-defining means andsaid station areadefining means and including conduit sections disposedto direct air under pressure to said guideway and into said plenum tolevitate said vehicle and propel said vehicle in one directionlongitudinally .of said guideway,

(f) said conduit means including other conduit sections adjacent saidstation area and disposed to propel said vehicle toward said stationarea,

(g) and valve means for controlling passage of air through said otherconduit sections, whereby said vehicle is propelled selectively towardsaid station area or along said guideway in laterally spaced relation tosaid station area.

20. The structure defined in claim 19 in which said guideway furtherdefines a vehicle deceleration area and an acceleration area eachdisposed at an opposite end of said station area, said other conduitsections being disposed in said deceleration area in a row extending atan oblique angle to the longitudinal dimension of said guideway towardsaid station area, and in which said conduit means further includesacceleration conduit sections-disposed in a row at said accelerationarea extending from said `station area toward said guideway at anobliqueangle to the longitudinal dimension of' said guideway, said accelerationconduit sections `being disposed to direct air under pressure throughsaid guideway delining means and into said plenum in a direction topropel said vehicle away from said station area toward said guidewayangularly of said one direction longitudinally of the guideway.

21. A pneumatic propulsion transportation system comprising:

(a) wall structure defining an elongated cross-sectionally generallyU-shaped guideway having opposed side walls and a bottom Wall and allongitudinally extending air duct underlying said bottom wall,

(b) a transportrvehicle having a bottom portion disposed on saidguideway for movement of said Vehicle longitudinally of said guideway,l

(c) said vehicle bottom portion cooperating with said bottom guidewaywall to define a plenum,

(d) means for supplying air under pressure to said duct,

(e) said guideway bottom wall having longitudinally spaced openingstherethrough for -directing air from said duct to said plenum in adirection to levitate `Said vehicle and propel saidy vehicle in aforward direction longitudinally ofy said guideway,

(f) a portion of said guideway being laterally extended to providea'station area at one sideof the guideway and deceleration andacceleration areas each at an opposite end of said station areaelongated in the direction of said guideway,

(g) and means for selectively moving` said vehicle from said guideway to-said deceleration area and toward said station area or permitting saidvehicle 20 to be movedalongrsaid'guideway inlaterally spaced relation tosaid -station area.

22. The` structure defined in claim 21 in which'said guideway 'bottomwall is provided rwitha row of deceleration openings in spacedrelation-generally longitudinally of said deceleration area, said rowextending angularly from said guideway. toward-said station area, said.deceleration openings bein'gdisposed to direct air from said duct tosaid deceleration area in adirection generally laterally away fromsaidguideway, saidvlast mentioned meansv including valves for opening andclosing said deceleration openings, and operating mechanism for saidvalves.

23. The structure definedy in kclaim Z1 in which said guideway bottomwallvis provided with arow of acceleration openings in spaced relationgenerally longitudinally ofv saidv acceleration area, said row extendingangularly from said station area toward said guideway, said accelerationopenings beingpdisposed t-o direct air from said duct toesaidaccelerationarea in a direction laterally towardl said guideway, saidlast mentioned means including valves for opening and closing-saidacceleration openings, and operating mechanism. for said valves.

References Cited by the Examiner UNITED STATES PATENTS 319,335 6/1985Smith 104-155 936,395 10/1909' Worthington 104-155 1,053,368A 2./19'13Bells 104'-15`5` 3,081,886 3/1963' Flexman et al. 3,090,327l 5/ 1963Crowley 1021-134 3,1683875 2/196'5 Reed f 104'-1'34 ARTHUR L. LA POINT,Primary Examiner.

MILTON BUCH'LER, Examiner. F. W. MONAGHN, Assistant Examiner.

1. A PNEUMATIC PROPULSION TRANSPORTATION SYSTEM COMPRISING: (A) MEANSINCLUDING A GENERALLY HORIZONTAL WALL PORTION AND GENERALLY OPPOSED WALLPORTIONS ANGULARLY DISPLACED FROM SAID GENERALLY HORIZONTAL WALL PORTIONAND DEFINING AN ELONGATED UPWARDLY OPENING GUIDEWAY, (B) A TRANSPORTVEHICLE DISPOSED IN OVERLYING RELATION TO SAID GENERALLY HORIZONTAL WALLPORTION FOR MOVEMENT LONGITUDINALLY OF SAID GUIDEWAY, (C) SAID VEHICLEHAVING A BOTTOM PORTION IN CLOSELY SPACED RELATION TO SAID GENERALLYOPPOSED WALL PORTIONS AND COOPERATING WITH SAID GENERALLY HORIZONTALWALL PORTION TO DEFINE A PLENUM, (D) CONDUIT MEANS INCLUDING A DUCTEXTENDING LONGITUDINALLY OF SAID GUIDEWAY, ONE OF SAID WALL PORTIONSHAVING A PLURALITY OF LONGITUDINALLY SPACED OPENINGS FOR COMMUNICATIONBETWEEN SAID DUCT AND GUIDEWAY, SAID CONDUIT MEANS BEING ADAPTED TO BECONNECTED TO A SOURCE OF AIR UNDER PRESSURE AND OPERATIVELY CONNECTED TOSAID GUIDEWAY DEFINING MEANS AND DISPOSED TO DIRECT AIR UNDER PRESSURETO SAID PLENUM IN A DIRECTION TO LEVITATE SAID VEHICLE AND PROPEL SAIDVEHICLE IN ONE DIRECTION LONGITUDINALLY OF SAID GUIDEWAY, (E) APLURALITY OF NORMALLY CLOSED VALVES EACH INDIVIDUAL TO A DIFFERENT ONEOF SAID LONGITUDINALLY SPACED OPENINGS AND EACH ARRANGED TO OPEN WHENDISPOSED DIRECTLY BELOW SAID VEHICLE AND TO CLOSE RESPONSIVE TO MOVEMENTOF SAID VEHICLE AWAY THEREFROM LONGITUDINALLY OF SAID GUIDEWAY, (F) ANDTIME DELAY DEVICES OPERATIVELY ASSOCIATED WITH EACH OF SAID VALVES TOHOLD SAID VALVES CLOSED FOR A PREDETERMINED TIME INTERVAL AFTER CLOSINGTHEREOF.